Chemical Vapour Deposition is a process to deposite solid coatings on surfaces by chemical reaction from gaseous compounds.

The reaction takes place on the surface of the substrate. To start the reaction the substrate needs to heated to high temperature. Many substrates, namely plastics do not have sufficient thermal stability for these reactions.

To avoid these high temperatures Depositon systems have been developped, where the reaction is generated distant from the surface and the reaction products are deposited on a relatively cold substrate.

The chemical reaction is stimulated by a low pressure plasma. The process is therefore known as a PECVD (Plasma Enhanced Chemical Vapour Deposition) or PACVD (Plasma Activated Chemical Vapour Deposition) process.

Important Applications for CVD processes are amorphous Carbon and Silicon depositions as well as Titannitride- Titancarbide- and Siliconnitride- Layers.